Casio Men's Pro Trek PRW3500 Solar Powered Atomic Digital Watch

Superb Watch - much more legible than others I've had of the same function type from Casio

The Casio PRW-3500 is one of the older models in Casio’s Pro Trek series of hiking watches. I believe it has been discontinued although it is still available for sale.This watch looks basic. It has no fancy graphics, just a digital display reminiscent of the 1980s. It is a solar-powered altimeter–barometer–compass (ABC) watch with a temperature sensor, world time, a stopwatch, a timer and alarms. It cannot connect to your smartphone, play music, count your steps, measure your heartbeat rate, or display your position on a map. If you want these features, this watch is not for you.This watch is for you if you want a rugged ABC watch that does not need recharging. Being digital, it has few moving parts so it is less likely to break down. Besides being solar-powered, it has a huge power reserve since it does not need to drive moving hands or light up an all-colour screen. According to the official specs a full charge is enough for seven months of normal use or 23 months in storage with power-saving on. I cannot verify these figures, but I have owned another Casio digital solar ABC watch (a PRG-270) for more than four years and in all this time it has never run low on power.The downside of the PRW-3500 is its user interface, which is also reminiscent of the 1980s. The basic altimeter, barometer and compass functions are activated by dedicated buttons on the right side of the watch case, so they are easy to use. But most other functions – for instance, calibrating the altimeter, using the timer, or logging ascents – are accessed through a sequence of button-presses that is non-intuitive and must be memorised. This makes such functions hard to use.However, I knew this when I bought the watch because my PRG-270 has a similar interface. The watch supplements a handheld GPS unit that supplies me with much of the information I need on hiking expeditions, so my use of the watch's ABC functions will normally be limited to those I can access with a single button-press (especially the compass) as a convenient alternative to digging into the menu of my GPS. I have used the PRG-270 in this way. It came into its own during a walking expedition in Wales last year, when I was crossing a stretch of boggy terrain with no clear path and no landmarks in filthy weather, and I used the watch to stay oriented in the right direction.The ABC functions do have to be used with a degree of caution. The watch compass sensor is accurate to within plus or minus ten degrees, so you may need a more accurate compass if you have to follow a precise bearing. Having said this, however, an approximate bearing is often enough. It has been so in all the scenarios in which I have needed a compass bearing, including my Welsh bog-traversing episode.The altimeter has to be calibrated often with reference to known altitudes at particular locations so as to take account of changes in air pressure due to weather. The temperature sensor works well only when the watch has been off your wrist for 20 to 30 minutes since – quite understandably – it would otherwise be affected by your body temperature. However, these issues apply to any ABC watch.The first thing I did when I received my PRW-3500 was to remove the resin watch band and replace it with a one-piece nylon “NATO” strap. The resin band is by no means uncomfortable, but if you have skinny wrists like me you will be left with a lot of extra length to catch on your sleeve and irritate you. With a nylon strap you can tuck the extra length inside the retainers. Also, the tongue on the resin band has a raised area which is intended to stop it slipping off but which makes taking off the watch awkward (first photo).Removing the resin band is relatively easy thanks to the screws on the watch lugs. 22-millimetre nylon straps make a perfect fit as long as they are not the heavy-duty type, which is too thick to pass through the gap between the pins and the watch body. Heavy-duty straps are overkill, however. Thinner straps are still tough and I have never had one fail on me.The PRW-3500 measures 56.9 × 53.4 × 14.5 mm, which makes it a big watch. However, it does not look as massive as these measurements would suggest. The watch face is dominated by its rotating bezel or ring, which is only 46 mm in diameter – barely larger than many men’s watches. The watch does not overwhelm my wrist, although its height is noticeable when seen from the side (second and third photos).The bezel has a practical use as a means to remember the bearing you have to follow if you are navigating by the watch compass. Aim the watch so the 12 o’clock position points in the direction you want to go, then rotate the bezel to align north on the bezel with north on the display. The bezel has just the right amount of resistance: it turns easily, but not so easily that it will turn on its own from contact with your sleeve. The raised segments on the bezel give you added grip when turning it with gloves on.Strictly speaking, the bezel is redundant because the watch compass has a bearing memory function that displays both your desired and actual bearing (fourth photo). However, I find the bezel simpler and easier to use.The PRW-3500 can calibrate its time-keeping to the second using radio signals transmitted from stations in England, Germany, China, Japan and the US, if they are in range. This feature is sometimes called atomic time since the transmitting stations keep time using atomic clocks. However, I do not live within range of any station so this feature is of no use to me.The PRW-3500 should keep time accurately even without radio calibration if the PRG-270 is anything to go by. I last set the time on my PRG-270 years ago (both models have a DST on-off feature and world time, so you don’t need to reset the time for summer or winter or if you travel), yet it has gone off track by no more than twenty seconds over all this period.Casio seems to be gradually phasing out the digital watches in its Pro Trek range in favour of analogue models. Its most recent models are battery-powered because they come with smart features that are too energy-hungry for solar power. This might make solar-powered digital hiking watches like the PRW-3500 a thing of the past, which would be a pity. Such watches display ABC information much more clearly than analogue models and they thrive on neglect, unlike smart watches. I have had my eye on the PRW-3500 as an eventual replacement for my PRG-270, so I decided to get it now while it is still available.

Excellent delivery timing, good size package, good quality for the price. Excellent seller. Whoever wants something like this the best choice to buy, highly recommended.